1. Field of the Invention
The present invention relates to liquid crystal aligning devices and alignment methods and, particularly to a liquid crystal aligning device used for alignment of transflective liquid crystal displays and an alignment method thereof.
2. Discussion of the Related Art
Liquid crystal display (LCD) devices have come into widespread use in recent years because of their advantages such as the ability to allow production of thinner devices and offer lower power consumption than display devices that utilize cathode ray tubes. Generally, LCD devices are divided into two types: a transmissive type and a reflective type. The transmissive LCD device utilizes light from a so-called backlight to provide a display. However, when the transmissive LCD device is used outdoors sunlight may make it difficult to see images on the display. The reflective LCD device, however, reflects outside light and utilizes the light to provide a display. In this way, the reflective LCD device is capable of providing a satisfactory display outdoors, but not in darker environments. Hence, a so-called transflective LCD device having the functions of both the transmissive and reflective LCD devices is receiving attention.
Generally, for improving quality of LCDs, alignment of liquid crystal molecules requires adjustment before use so the liquid crystal molecules achieve predetermined optical characteristics, for example, predetermined phase retardation. There are several methods of adjusting the alignment of liquid crystal molecules for single cell gap transflective LCD devices. For example, a method in which an organic film is formed on the surface of a substrate and rubbed in one direction with cloth to align the liquid crystals is typically used. However, when liquid crystals are aligned by rubbing, dust is produced or static electricity generated and both may cause a display failure. A photo-alignment method is therefore desirable in which a plurality of regions having different alignment directions can be formed.
A typical photo-alignment method requires performing two different photo-alignments on two indium tin oxide (ITO) substrates. Ultraviolet (UV) curing polyimide material is then coated on the ITO substrates by spin coating. After photo-alignment, two ITO substrates with different photo alignments are then bonded together and the liquid crystal molecules are filled therebetween so as to form a liquid crystal cell. In addition, for a transmissive area and a reflective area of the liquid crystal device, in order to achieve different predetermined phase retardation, two different curing voltages and multiple exposures should be applied to the liquid crystal device, which is difficult and time consuming.
Therefore, a new liquid crystal device and an alignment method thereof are desired.